Oxidative Potential of Logwood and Pellet Burning Particles Assessed by a Novel Profluorescent Nitroxide Probe

• Published in: Environmental science & technology 2010-09, Vol.44 (17), p.6601-6607
• Main Authors: Miljevic, B, Heringa, M. F, Keller, A, Meyer, N. K, Good, J, Lauber, A, DeCarlo, P. F, Fairfull-Smith, K. E, Nussbaumer, T, Burtscher, H, Prevot, A. S. H, Baltensperger, U, Bottle, S. E, Ristovski, Z. D
• Format: Article
• Language: English
• Subjects: Aerosols; Applied sciences; Characterization of Natural and Affected Environments; Emissions; Environmental cleanup; Exact sciences and technology; Fires; Fluidized bed combustion; Fluorescence; Fluorescent Dyes - chemistry; Molecular Weight; Nitrogen Oxides - chemistry; Oxidation; Oxidation-Reduction; Particulate Matter - chemistry; Pollution; Reactive Oxygen Species - metabolism; Spectrometry, Fluorescence; Studies; Temperature; Toxicity; Toxicology; Wood - metabolism
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es100963y

This study reports the potential toxicological impact of particles produced during biomass combustion by an automatic pellet boiler and a traditional logwood stove under various combustion conditions using a novel profluorescent nitroxide probe, BPEAnit. This probe is weakly fluorescent but yields strong fluorescence emission upon radical trapping or redox activity. Samples were collected by bubbling aerosol through an impinger containing BPEAnit solution, followed by fluorescence measurement. The fluorescence of BPEAnit was measured for particles produced during various combustion phases: at the beginning of burning (cold start), stable combustion after refilling with the fuel (warm start), and poor burning conditions. For particles produced by the logwood stove under cold-start conditions, significantly higher amounts of reactive species per unit of particulate mass were observed compared to emissions produced during a warm start. In addition, sampling of logwood burning emissions after passing through a thermodenuder at 250 °C resulted in an 80−100% reduction of the fluorescence signal of the BPEAnit probe, indicating that the majority of reactive species were semivolatile. Moreover, the amount of reactive species showed a strong correlation with the amount of particulate organic material. This indicates the importance of semivolatile organics in particle-related toxicity. Particle emissions from the pellet boiler, although of similar mass concentration, were not observed to lead to an increase in fluorescence signal during any of the combustion phases.